Subesha Singarajah
Brookside Science & Technology Grade 8 Lesson Plan
Presented on: March 3, 2011 (Day 3)
Science and Technology (45 Minutes)
Lesson 3: Density Experiment
Grade 8
Overall Expectations: Investigate the properties of fluids & Demonstrate an understanding of
the properties and uses of fluids.
Materials
Specific Expectations:
Developing Investigation and Communication Skills
2.1
Follow established safety practices for using apparatus, tools, and materials
(e.g., use syringes and tubing for the purposes for which they were designed)
2.3
Investigate and compare the density of a variety of liquids
2.7
Use appropriate science and technology vocabulary, including viscosity,
density, particle theory of matter, hydraulic, and pneumatic, in oral and
written communication
2.8
Use a variety of forms (e.g., oral, written, graphic, multimedia) to
communicate with different audiences and for a variety of purposes
Understanding Concepts
3.2
Describe the relationship between mass, volume, and density as a property of
matter
3.3
Explain the difference between solids, liquids, and gases in terms of density,
using the particle theory of matter (e.g., in general, solids are more dense than
liquids, which are more dense than gases)
3.5
Determine the buoyancy of an object, given its density, in a variety of fluids
Lesson Expectations: In this lesson students understand the basics of density through a
student lead experiment. Students will be given the introduction to the experiment, they will
then make decisions on how they will complete the experiment set up. Students will have to
complete a worksheet answering questions regarding the experiment to show their
understanding of Density.
Experiment
Worksheet
Handout
Beakers
2 Eggs
Saturated Salt
Water
Food Colouring
(Per group – 8 in
total)
Graduated
Cylinder
Ethanol (15ml)
Saturated Salt
(15ml)
Vegetable Oil
(15ml)
Bead, Penny &
Cork
Time: (40 mins)
Assessment Opportunities
Ask students to hand in their density worksheet.
Participation
Intro
Egg Race: Have two beakers set up on front bench – one will have pure water
5-7 mins
the other will have saturated salt water (Don't label them). Have two eggs, ask
one student to come up and have a race with you. Student will drop egg into
the saturated salt water, teacher will drop it in pure water. Ask students why
the egg is floating in the salted water. Ask student to put food colouring into
the salt water. Ask them what they think will happen when you put pour
water on top of the salt water. Pour water into the salt water coloured + egg.
Tell students they will be doing a similar experiment to this and doing a write
up for it which is due for homework on Friday March 04, 2010.
Explain Experiment + Safety rules + Worksheet.
Group work
Action!
35 mins
 Students will be working in groups – each group will have One
Experiment –
graduated cylinder, 1 test tube with 15 ml Vegetable oil, 1 test tube
Summative
with 15ml saturated salt, 1 test tube with 15 ml Ethanol, Cork piece,
Evaluation
penny, bead and worksheet(for each group member).
Subesha Singarajah


You’re going to work as a group to determine which substance you
will put first into your graduated cylinder. You need to explain why
you choose one over then other on your worksheet. Density of each
substance can be found on your worksheet as well.
Each group will need to pick one person to be the material person –
once they decide that person is to put up their hand.
Ethanol Material Safety Data: Ethanol, also called ethyl alcohol, pure
alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless
liquid. Ethanol has widespread use as a solvent of substances intended for
human contact or consumption, including scents, flavorings, colorings, and
medicines. In chemistry, it is an essential solvent. Skin Contact - Irritating to
skin. Wash contaminated skin promptly with soap or mild detergent and
water. Irritating to eyes. Can be damaging if large amount is splashed into
eyes. Wash eyes promptly with plenty of water, while lifting the eye lids.
Continue to rinse for at least 15 minutes, and get medical attention.
Intoxicating if ingested. (If ingested in undiluted form, it has a severe drying
effect on mucous membranes of mouth and throat.) Wash out mouth
thoroughly, and give plenty of water to drink. Do not induce vomiting. Get
medical attention immediately.
Debrief
If time
permits
give this
question
for
students
to think
about
Differentiate
Give students rest of time to complete their experiment write up worksheet.
Tell them Good luck and ask for any feedback.
Ask students a question: Which is more dense water or ice - take a vote. Ask
students to explain their answer.
Teachers Notes: A substance floats if it is less dense, or has less mass per unit
volume, than other components in a mixture. Water reaches its maximum
density at 4°C (40°F). As it cools further and freezes into ice, it actually
becomes less dense. On the other hand, most substances are most dense in
their solid (frozen) state than in their liquid state. Water is different because
of hydrogen bonding. When water freezes, the molecules crystallize, with the
space (Volume) between each molecule increasing. If the mass of water does
not change, this has the effect of decreasing the density of frozen water. It is
for this reason that ice floats on top of water, as seen in the frozen surfaces of
lakes and in icebergs. When the ice melts, the density increases again. This is
an important effect for roof stability: when ice and snow collect on a roof and
melt, the increased density of the resulting water can be enough to collapse
the roof.
This lesson is hands on; students will first see a visual representation of a
similar experiment (model) but then will work in groups to figure out how
their own experiment will be set up.
Experiment
Worksheet